A conventional tablet package has a base sheet provided with a plurality of blisters and flanges extending around the blisters, and contains tablets in the blisters. Tablets are put in the blisters and the blisters are sealed by attaching a covering sheet by heat-sealing to the flanges of the base sheet.
Tablets are put in the blisters formed in the base sheet, and then the covering sheet is bonded to the flanges of the blisters formed in the base sheet by heat-sealing to obtain a package (PTP package). The base sheet and the covering sheet of the package are perforated to divide the package into a plurality of unit blister packages each having the blister containing the tablet and covered with a section of the covering sheet. The package can be torn along the perforations to separate each unit blister package from the package.
The base sheet is made of polyvinyl chloride (PVC) or the like and is relatively thick to hold the tablets securely, and the covering sheet is relatively thin as compared with the base sheet.
The unit blister package is separated from the package by tearing the base sheet and the covering sheet along the perforations, and then the section of the covering sheet is torn off to take out the tablet from the blister.
Incidentally, it sometimes occurs that a user swallows the unit blister package containing the tablet without taking out the tablet from the blister. If the unit blister package is swallowed, the edges of the flange made of the relatively thick base sheet may possibly injure the internal organs of the user and bring about very dangerous circumstances.